As you can see we take security really seriously too:
compojoom.com/blog/news/hack-compojoomcomment-and-win-a-prize
There have been 6 reported security problems - 5 of them are fixed in 4.1.5 and the last one will be fixed today and we will release 4.1.6.
All previous versions including 4.0 are vulnerable.
Cheers,
Daniel
P.S. If you write to me (here or in an email) why 15€ is too much on your side ( and if it is a reason like - live in Africa or earn 50€ per month) I will grant you a free subscription.